The present invention relates generally to gas meter exchange systems. More particularly, the present invention relates to a method and apparatus for replacing a gas meter without interrupting customer gas service.
As will be appreciated by those skilled in the art, gas meters, and meters used by other utilities, must be periodically replaced in accordance with routine maintenance programs. It is customary to replace meters when their accuracy is questioned. Meters typically are routinely replaced when aged beyond certain limits.
An obvious and outdated approach is to simply remove the old meter without any attempt to maintain customer service during maintenance. Removal is effectuated by loosening the swievel nuts which couple it to the meter loop. The meter is then quickly removed and its replacement may then be reinstalled. However, it will immediately be recognized that this conventional meter exchange technique results in an at least temporary interruption in gas service. Hence certain gas appliances may require pilot light reignition after the replacement meter is appropriately installed. The service or labor costs of first turning off and then re-lighting all of the pilot lights which may be found at a particular customer location may be significant. With older gas operated appliances such as water heaters the pilot light may not be easy to reestablish after service interruption. This may be caused by aging safety thermo couples which close the gas flow in the pilot flame line in response to sensed temperature loss occurring during the interruption. In such cases reestablishment of the pilot flame will be exceedingly difficult and/or expensive, if not impossible.
Consequently it has been suggested in the prior art to provide a system for changing meters which will facilitate meter replacement without interrupting service. However, all known prior art attempts have required the use of special accessory pipe fittings of various forms which must be installed at all service locations. For a gas utility company, for example, to properly employ such technology, all existing service locations must be modified or replaced with "non-interrupt" accessory hardware. The cost factors in such a massive adaptation are prohibitive. Examples of prior art of the latter type may be seen in U.S. Pat. Nos. 3,122,158; 3,148,690; and 3,438,397.